Vitreopapillary Findings in Nonarteritic Ischemic Optic Neuropathy versus Healthy Eyes: A Clinical and OCT Comparison.

Abstract

To study the vitreopapillary interface in nonarteritic ischemic optic neuropathy (NAION) for features that may predispose to optic nerve perfusion defects. Case-control study. Patients with NAION (study group) were compared with healthy non-NAION patients with crowded discs (control group I) and noncrowded optic discs (control group II). The vitreopapillary interface was studied in 32 eyes with NAION using high-resolution OCT scans. Results were compared with 2 control groups consisting of age, sex, and refraction-matched non-NAION individuals with crowded optic discs (control group I: 31 eyes) and noncrowded optic discs (control group II: 32 eyes). The incidence of total posterior vitreous detachment (PVD), vitreopapillary and vitreovascular attachments, and epipapillary membranes. The rate of PVD over the macula was similar between groups (NAION: 62.5%, control I: 61.3%, and control II: 65.6%, P = 0.93), whereas the posterior hyaloid remained attached to the crowded discs at a significantly higher rate (NAION: 81.2%, control I: 83.9% and control II: 43.7%, P = 0.0005). A higher rate of focal vitreopapillary attachments on crowded discs than on noncrowded discs was noted (NAION: 72.2%, crowded control I: 58.7%, and noncrowded control II: 19.1%, P = 0.007). Vitreovascular attachments (NAION: 68.8%, crowded control I: 3.2% vs. noncrowded control II: 6.3%, P = 0.00001) and dense epipapillary membranes were observed in NAION eyes. Crowded discs may have stronger vitreopapillary attachments. A close relationship of these attachments with optic nerve vessels may lead to the transmission of strong tractional forces by a syneretic vitreous gel, especially after macular PVD. This transduced mechanical force may contort the vessel wall and disrupt the blood flow in NAION. Proprietary or commercial disclosure may be found after the references in the Footnotes and Disclosures at the end of this article.